French researchers have succeeded in controlling the activity of nicotine receptors in the brain using different lights. Explanations.
One more step against smoking. A new study from Inserm has just demonstrated that it is possible to manipulate nicotine addiction in mice, in a rapid and reversible manner.
“This innovative technology makes it possible to better understand the role of the different nicotinic receptors and the different neuronal pathways in the establishment and maintenance of nicotine addiction, but also in the processes of withdrawal and relapse. This step is particularly important. important for the identification of new therapeutic targets suitable to fight against addiction nicotine “, specifies Alexandre Mourot, head of research.
Purple light helps stop the attraction to nicotine
Nicotine, the main addictive agent of tobacco, acts on the brain by binding to nicotinic receptors. Based on this premise, the scientists modified the nicotinic receptor in mice, in order to be able to attach a chemical nano-switch reacting to light. Under the effect of the violet light, the switch folds up, preventing the nicotine from attaching itself: the receptor is “off”. Under the effect of green light, or in the dark, the switch is unfolded and will thus let the nicotine act: the receptor is “on”.
Concretely, the purple light makes it possible to stop the attraction for nicotine. The team compared the time mice spent in two compartments, with or without nicotine. Under green light, when nicotine can exert its effect, they observed that the animals preferred the compartment with nicotine. Under purple light on the other hand, the mice spent as much time in each compartment, proving that they were no longer attracted to nicotine.
A particular nicotine receptor
For this study, the researchers focused on a particular nicotinic receptor, the b2 type, and on a key area of the reward circuit, delivering dopamine. During an intravenous injection of nicotine, dopamine neurons respond with an increase in their electrical activity. The dopamine release ensuing is the key to building addiction.
Nicotine is a chemical compound naturally present in tobacco plants, which is part of the alkaloids. Its properties for the plant are to ward off parasites (fungicide, acaricide, insecticide). In humans, nicotine causes dependence on tobacco as well as feelings of relaxation, pleasure, reduced anxiety and depression. depression.
When you smoke, there is an initial “peak” during which the concentration of nicotine in the body increases continuously, until the cigarette is completely burned, ie between 5 and 7 minutes. Then, this concentration decreases rapidly: after an hour, it decreases by half; after two hours, only a quarter of the initial peak remains in the blood.
The damage to the younger generations
However, there will still be some traces of nicotine in the body. After 4 days, the blood will have purged all of the nicotine it contained. The other derivatives of nicotine and tobacco, which are responsible for the urge to smoke (cotinine, anabasine and nornicotines) take much longer to eliminate in certain organs of the body, such as the kidneys or fatty tissue. It takes an average of three weeks to be completely free of traces of nicotine, the product being evacuated mainly via urine.
The damage to the younger generations can thus be considerable. According to a very recent study, the arteries of adolescents who smoke start to stiffen as early as the age of 17. Arterial stiffness indicates that the blood vessels are starting to be damaged, which is the bedrock of future heart and blood vessel problems. We are talking about heart attacks orstroke.
“In France, more than 13 million people smoke”, declared the government last March, recalling that tobacco is a “major source of cancer, cardiovascular diseases and respiratory insufficiencies, responsible for 73,000 deaths each year. “. Every day around the world, 11 million cigarettes are sold, generating 39 billion in profits, the equivalent of Luxembourg’s GDP.
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